[ Strands before (left) and after (right) applying a surface comb modifier ]

Creating fur requires a different approach than that for creating longer hair. Fur covers a lot more of surface area and tends to be very short. Because of the sheer number of fur strands it becomes increasingly difficult to control them via brushing and guide manipulation. Furthermore most fur follows a pattern of flow along the surface that can be reproduced without having to manipulate the shape of every guide. Also because fur is relatively short it usually doesn't have a very detailed shape but rather a generic curvature which is inherited by nearby strands.

[ Surface comb with slope (left) and directional sink (right) parameters changed ]

Surface comb takes advatnage of these features about fur and provides a method for easy, fast, and intuitive manipulation of shape and flow of fur along arbitrary surfaces. Every fur strand is combed procedurally in two ways- perpendicular to the surface and parallel to the surface.

Perpendicular (longitudal) combing is controlled through a comb curve diagram and an optional map. The value controlled is 'sloping' that is applied to strands to bring them closer to the surface tangent. Maps can be used to randomize or control the strand shape differently in different parts of the model.

[ One omni-directional sink (left) and two directional sinks (right) are used to direct hair ]

Parallel (azimuthal) combing can be controlled via maps and/or via virtual objects called sinks. Sinks can be placed arbitrary in space and on the mesh surface and act as magnets that either attract or repel the hair in their area. Maps can be combined with sinks to randomize the hair flow. Furthermore you can control the random factor of fur (to create frizziness) with a chaos parameter.

[ A combination of omni and uni-directional sinks ]

Parameters:

Azimuthal deviation - The randomness of hair direction along the surface.

Surface orientation - You can control whether every strand's orientation is deviated locally or globally relative to the whole object. If you specify an orientation map, you can control whether orientation is assigned per hair segment, or to the whole hair as a whole.

MXS Access:

Interface: OrnaSurfaceComb

Functions:

.CreateSink ()
.DeleteSelSinks ()